Temperature responsive control means



y 1934- v. E CARBONARA 1,966,843

TEMPERATURE RESPONSIVB CONTROL MEANS Filed Dec. 5, 1931 2 Sheets-Sheet l INVENTOR ATTORNEY July 17, 1934. v. E. CARBONARA TEMPERATURE RESPONSIVE CONTROL MEANS Filed Dec. 5, 1931 2 Sheets-Sheet 2 INVENTOR l fcfar E. Carbo/mm BY J ATTORNEY I 55 gpon mofthe'device. I a

Patented July 1 7, 1934 "1';966; 3.f DEMTERATURE IRESPONSIVE common t q -MEANS,- a; :Victor'E. Carbonfim, Rockvilie o ens. 1., a'sj signer toBendixfAviation Corporation, South IBenHJfFnd co n rationor llelawere ghm' um mi -mwiiiieijirs, 1931,. saw. 51933: swims," (01. 200 141) 'ZIIhe pnesent :invention :relates to temperature responsive :co'ritrol meansgand 'more particularly to thermostaticzcircuit closersof the type'which, while :susc'eptibleuof .other uses, are especially l euaptedxforractuating electric zfirezeia'mr systems.

a illhez-inventiomembodiesaitemperature responsiveelement of theithemlometer type for :closing zan electriccircuit'when the mercury col'umnrises to so iireightucorresponding to .a predetermined #1. xenmerature zattwhich said electric cirouit'is to be closed for producing an alarm signal which may be (either :audible arr Ivisual; .iBroadly, temperature responsive devices of his typeihave long been :knownin .thex'art land have been employed -18 mithalarge measure :ofzsucoess innthezopera'tion -thereof, but the thermometer? element has been susceptible rtobreakage :due' so :the i peculiar :com- ,stmction of the devices,"inwhichttheeleinentapro :jected'nutwardlyirom its support. 1

Accordingly, one 16f the objects or like mat i'invention :is to provide :a, Enovel itemperature 11essponsive control device wherein :the thermometer element-is irpmtected :trom :breakage and whereby itheipmtecting'means also asrheatecozrduct- .ingmeansrfonrendering theadevine moresensitive.

. mothermhieotrof :the inventicmisrto'provide a novel temperature responsive circuit closer or the mercury type adapted :to nloseta oircu'rtof a ball or othdrrsuitable'signalwheneverthe temper- .30 attire 1ot-the :surroundinglair *to aipredeter against antranoe'of-air, moisture, or; other'foreign substances which would impair the, efficiency and reliability 0f the device. A still further object is tmprovide noml mountingmeansior a deviceoi thewforegoing character,

- '45 -which means facilitate theunstallation or, removal of the :device .as wellas enhancingits taccessibilityandmdaptahilitya H g .Anotherpbjectis-to provide novel mounting v n ieansif the-,ahove type which may [also serve as '60 the currentdeeding means. V r p f Another objectof the .inyention is toprovidein iadevice oi the class described, a novel construction :embodying roombined :protectingand- :heatconducting eans for the mercury containing istillanotherobject is toYptovi'de a novel method of manufacturing a thermostat of the mercury type whereby the device is so constructed :as to terminate inra lamp base of the eharactercomrmonly employed ain incandescent electric lamps. Q0

The above and other obiecisand advantagesof the invention will appear more .fully hereinafter iromna consideration of :the 'detailed description which iiollnws, it'aken together with the accomnpanying drawings, wherein itwo embodiments of the invention-are. illustrated. It is to be expressly understood, Zhowever, ithat =the drawings are for the purpose ofiillustration and description aorily,tand are 'not designed :a's audefinition of the limits :of the invention, reference being had for this purpose to the appended claims.

isIn-theidrawings, wherein like reference chararctersrefer to -.likeirpa.rts throughout the several views, i g

.i-isxan elevational view, partly in section, of one-form ozfxlevice embodyingtheipresent in- :vention; Y

:Fig. :2 is. a :.'plan view, "looking upward, or the devicezshowhin Fig. ;I; I

tFlig.3 is:anelevationypartlvin section, ofanother 'form of device embodying the invention; I yfE'ig. isi-arplan viewsimilar to'that shown in :.5 'is a detail plan looking I downward in 3 on the 'baserof "the device; and.

Fig. 6 is a perspective wiew ofthe b'ase shown :in-Figx4. a I r l Referring to the drawings, and more particu- .larlyatoiligslzand 2,1t-will be seen that, in the iurmcshown therein, the invention is embodied 590 -in. iaadevioeuincluding 1a vessel or capillary tube 5 of the. thermometer type, preferably of glass and lcontaining'a quantity of mercury or other substance having iihe desired quaiities, the tube 5 terminating in aimercurywontainingbulb 6 to which is *fused 7U) :otherwise integrally formed an =envelope 7 cut glass or other suitable 'transparent lmaterial.-.- iillhirupper endof'the envelope 'Tis ceoriented or isuitably molded into a metallic base -8:sin'a1 "manner similar itowthat employed in the manufacture 0f iinoandenscent electric lamps. The air in the envelope '7 :maybe evacuated in "the usual mar'mer for the :purpose of preventing the temperature l'responsive devic'e trom beo'oming inoperative 'in-ithe '.event-any'. lea;ks should occur around 1 theiterminals or electrodes extending into the capillary tube 5 which provides contact with mhewmercury in a:manner ;and .fcr .a :purpose to be described hereinafter." 1

thermometer tube and envelope and the novel securing means just described, the invention further contemplates, as suggested above, the provision of a novel current-conducting means for operating an annunciator or alarm-sounding apparatus with which the device is adapted to be employed, on a predetermined rise of temperature. In the present embodiment, such means preferably include a pair of electrodes 11 and 12 suitably secured within the Wall of the tube 5 at properly spaced points, as shown, depending upon the temperature at which it is desired to close the electric circuit, said two electrodes having extensions or leads 13 and 14 which are fused to the upper end of the envelope '7 and connected to terminals 15 and 16 extending from the metal base 8. Terminals 15 and 16a are fixed in suitable insulating material (not shown) provided in the base, and arranged in position to register, upon insertion of the device in an insulating socket 18, with associated terminals 19 and 20, respectively. The latter terminals may have connected thereto suitable conductors leading to a bell or other signal producing element of the system, the particular form of which is immaterial to the present invention.

Any suitable means may be employed for providing a looking but readily detachable connection between the base 8 of the thermostat device and the socket 18, but it is preferable to employ a lock of the bayonet type, as indicated in Fig. 1, and comprising a pin 21 on the base 8 cooperating with a slot 21a in the socket 18. Likewise, any suitable means may be employed for securing the socket 18 to the sealing or other support 22.

Novel means are provided for protecting the breakable portion of the device, namely, the glass envelope 7 and the thermometer tube 5, which means also afford efficient heat-conductance for insuring proper response to the thermometer to the surrounding air, and in theform shown comprise a plurality of thin downwardly extending and radially disposed protective members or fins 23 which may be triangularly shaped as shown in Fig. 1, and are mounted so as to present their inner edges, as indicated at 24, adjacent the wall of the evacuated envelope 7 in order to protect said envelope and the thermometer tube 5 without interfering with radiation of heat to the mercury in the bulb 8.

In the present embodiment suitable supporting means are provided for the guard members 23 which, as shown, take the form of a circular flange 28 integral therewith and adapted to register with a similar cooperating flange 29 on a cylindrical base 30 secured to the support 22 in any suitable manner, as by means of screws 31 and the flanges 28 and 29 being likewise secured together by means of screws 32.

Referring to Fig. 3, there is shown another form of device embodying the present invention, in which the guard members or protecting fins 33 are of somewhat different form from those shown in Fig. 1 and are formed integral with an extension 34 forming a support for the socket member 35. In this embodiment the evacuated vessel 7 is secured permanently in the socket member 35 in any suitable manner, as by means of an adhesive mass 36 such as porcelain cement. The lead wires 13 and 14 are brought out from the socket 35 through openings 37 and connected in any suitable manner, as by soldering, to metallic strips 38 and 39, and placed in grooves 40 and 41 formed in the socket member 35 and secured to the latter in any suitable manner, as by means of screws 42. The metallic connections 38 and 39 are provided with terminal or binding posts 43 and 44 for connecting the thermostat to any suitable signal alarm circuit. The screws 42 also serve to secure the socket member 35 to the extension 34. The entire assembly may be mounted in a casing or cover 45 and secured to the latter by means of screws 46 engaging with lugs 47 formed integral with the cover 45.

It will be seen, in both embodiments, that when the mercury rises in capillary tube 5 due to a rise in temperature the gap between the electrodes 11 and 12 will be closed, thereby closing the electric circuit to the alarm device.

From the foregoing it is apparent that the invention provides a temperature responsive circuit closer of novel construction which is relatively simple and may be easily installed, and one which is not subject to the deteriorating influence of moisture or air, or easily broken. Heretofore, efforts have been made to seal thermostats of this character against the admission of air or moisture, by the use of sealing liquids, sealing wax, and similar substances, but these are obviously of uncertain eiiiciency as compared with the method used in the manufacture of incandescent lamps, the application of which method to a device of the character herein disclosed constitutes one of the novel features of the present invention.

Although only two embodiments of'the invention have been illustrated and described, other changes and modifications, which will now appear to those skilled in the art, may be made in the construction and method of assembly and operation of the parts of the device herein disclosed without departing from the scope of the invention, and certain features of the invention may be utilized independently of others, as for example, the guard may be varied in shape and form and an inert gas such as neon introduced into the vessel to produce a luminous effect whereby the device may serve as an indicator as well as a. thermostat. Reference is therefore to be had to the appended claims for a definition of the limits of the invention. 1

What is claimed is:

1. In a device of the class described, a tube having mercury therein; a pair of conducting leads secured in the wall of said tube in a position to contact with the mercury upon its rising to a sufiicient height therein; closure means for said tube and said leads comprising a second tube surrounding said first named tube and merging therewith at its lower end; and means at the upper end of said second named tube for securing said leads in insulated relation to each other, said second tube being evacuated and sealed against the entry of air or moisture to prevent the inoperation of the mercury within the first tube in the event leaks occur in said first tube around the conducting leads.

2. In a device of the class described, a tube having a bulb at one end thereof filled with mercury; a pair of conducting leads secured in the wall of said tube in a position to contact with the mercury upon its rising to a suflicient height therein; closure means for said tube and said leads comprising a second tube surrounding said first named tube and merging therewith at its bulb end; means at the upper end of said second named tube for fusing said leads in insulated relation to each other and completely sealing'said tube against the entry of air, the space formed between the first and second tubes being evacuated to prevent inoperation of the mercury within the first tube in the event leaks occur in said first tube around the conducting leads; and means enclosing said last mentioned means and having guard means thereon in the form of fins extending radially from the common axis of the two tubes to prevent breaking of said tubes and to afford efficient heat transmission to the device from the surrounding air.

3. A device of the class described comprising a tube having a heat responsive fluid therein; a second tube surrounding said first named tube and merging at one end therewith; a base of insulating material secured to the other end of said surrounding tube; a pair of current conducting leads secured in the wall of the said first named tube and terminating in contacts firmly held in said base, said heat responsive fluid being adapted to close an electric circuit through said leads, the space formed between the first and second tubes being evacuated to prevent the inoperation of the mercury within the first tube in the event leaks occur in said first tube around the conducting leads; and external protecting means for both said tubes comprising a plurality of fins extending downwardly from the base and disposed radially with their inner edges adjacent the second tube so that they afiord eflicient heat transmission from the surrounding air to the device while protecting the same.

VICTOR E. CARBONARA. 

